Water cooler



May 19, 1953 R. ERWIN ET AL 2,633,751

WATER COOLER Filed April 17, 195 0 5 Sheets-Sheet 1 RECEIVER CONDENSER COMPRESSOR L 5'5 ROY ERWIN 8 JOSEPH B. GRIFFITH. INVENTORS.

HUEBNER, HE E HLER, WORREL;

HERZ/G 8 CALDWELL; ATTORNEYS.

May'l9, 1953 L. R. ERWlN ET AL WATER COOLER 5 Sheets-Sheet 2 Filed April 17. 1950 LEE ROY ERW/N 8 JOSEPH B. GRIFFITH,-

//vv/v TOPS. HUEBNER, BE E HL E R, WOR'REL,

HERZIG 8 CALDWELL By ATTORNEYS.

May 19, 1953 L. R. ERWlN ETAL WATER COOLER 5 Sheets-Sheet 5 Filed April 17, 1950 LEE ROY ERW/N 8 JOSEPH B. GRIFFITH,

wvavrons. BEEHLER, WORREL HERZ/G 8 CA L0 HUEBNER,

WE L L 9 A T TORNEVS.

May 19, 1.953 L. R. ERWIN ETAL WATER COOLER 5 Sheets-Sheet 4 Filed April 17, 1950 LEE ROY E'RW/N d JOSEPH B. GRIFFITH,

, lNl/EN TORS.

HUEBNER, BEEHLER, WORRE L HE'RZ/G 8 CALDWELL, ATTORNEYS.

A TTORNEYS.

5 Sheets-Sheet 5 LEE ROY ERW/N a JOSEPH 8. GRIFF/ HERZIG 8 CALDWELL,

L. R. ERWIN ETAL WATER COOLER Fwww May 19, 1953 Filed April 17, 1950 Patented May 19, 1953 of Delaware Application-'Apri1 17, 1950;Setiail N'Du1'56332 Our. invention *relates to water cooler and" has particular reference to the details o'f construcliionwhereinWater-maybe substantially-fin stantaneously co'oledf particularly wl iere 1 large T volumes of refrigerated water'are needed.

One -of--the objects er our invention is to produce a water cooling" systernj wherein water in substantially large volu'mes -cari-2be coo1ed diir ingthecoursed-travel"through the cooler with out the necessity of storage of wateriin tank while being-cooled; andto-cool-s1icl-'i Waterio Within a fraction of a degree of the temperature ofthe refrigerant being employed.

We have-employed *a flooded coil' type refr'igeration'isystern; wherein circulation" of a -liquid refrigerant through the refrigerating system is" causedby' conve'ctioneurrents and whereby -the heat transferred. from the "water to the re'friger ant is greatly increased" because' J of- ='liquid-='to metal contact rather-than "the contact-ofgaseous refrigerant which isslower' in heat transfer. We employ the term floodedcoil in the cle'scrip== tion ,and claims' in the generally aceep'teii meaninglto .disting.1iish"fr0m ardryTcoil systemy-th'e" Word coil havingznc referenceitothe specific" form o'fthe tube .or tubes throughwhich there-- frigier'ant travels; The coil illustrated in i the Figure 5 is an enlarged fragmentary sectional-i viewrtakenondine 5+5 of. Figure 4.

Figure v6 zisia'zsectional' view 'taken on 1inea.6.--6 of Eig'urewZi t Figure H is; ansectionalrview taken on line-1+1 of Figure 2..

Figure 8 is ia;sec.tional-' elevationiof -a modified formlof heat' 'exchangercr Figure 1'0 is: a :sfr'agmentary 1- sectionaL releva-w tion i of a viiurther modification rlcf: i: a heat. --'exchangers? Figure- 11:1 lists aissectionaliviewlitakenvon dine- Il--H of Figure 10.

Tillie :pref'erred cform of :our: vinventionwinclucles asystem'ihav'ingia compresscrni0,ia%condenserl-i; areceivier 1:2,randaliquidmefrigerant:tankonhead 3. Ansexp'ansion value Hl riswintenposed be-s:

tweeri theereceiver 1L2 iandnthezliqiiid Frefrigenant' tanh 'or iheader ii fi sand :is adapted toxcontrolnthe admission xofs-xliquid refrigerant from the 'TBGOiVBI": int'e' theiheac'ier elf-a Thelheader :l 8 :is formed 'witha fii'epe'nding acy'lindr'icalcleg al 5} connected rat the lowerentl to aheat-exchangecumin-designated generally 15, l whichwsaidfiheatz iexchangeraunit is aiiapteli to passmeirigenant batik into theiheader present disclosure" comprises "'a plurality o! [3, Thec-header lii'ialsncfliasxa, ese ondedepend-e straight tubes. ingleg lji'whichipasses(througha:secoml heaitfI-he refrigeration system contemplated em ploys a "tank "for liquid refrigerant*into'vvhich the flooded coils areattached and has meansfon controlling the level of "liquid refrigerantin said tank, whichsaid means is responsive to the-tem per'atnre of the .watehbeing introduced irito-the cooling systemso thatinthe event the Water is" initially. introduced at a higher "temperature, greater amounts "of liquid refrigerants are 'in troduced "intothe system- 170 thereby-compensate for the increased l'oachor heat which must beremoved."

Other and. further objectsand advantages will "become apparent from the drawings and specifications relative thereto.-

.In the drawings-: 7

Figure 1 is 'an-elevational'viewof a waitercooler 1 exchan'geumit I 8 .ancl iipwardly to ithetcompressor to return the ispenlt or warmed mfriger2sntrback-- to t1ie= comp1essorofor*rcompletion .of another cyclea n The compressor 'condenser sand :receiver form:

' no pai t f:fcheiinventionitand are nshewn scheimati'c'aillz' 2in ronderdtocorient our invention and: to show a complete refirigeizatiiigrsystemn "zersentiai v idetailsil :of; sour :preferred form are shown more clearlyiin Figure. 2.

The hader 71 3 is ffermed with anvinletenipple 2U, to whi'ch a kconluit-az 'sirconnecterlranddeadsh such as zz is' iritroduc'erlithroug hithe pipeEZ-I iritoa:

the header I3.

headerx I 3 iis: iormedcwithran opening at the bottom itheredf adapted to ifp'er'mit therc-yli'nembodying the principles of= our inventioir and dricalmcolum WI-'5 tflibeainsefledrtherflifii n;;fiuid-:- being-partiallyschematic insofar as the rejrig ti' xh el tionwarrd tolipermim; mnmiimtiun ofia eraiiicnsystemis concerned. the iquid firefrigerrant-lzz iidownwardly through' Figiire 2 an "elevational view; partly "in "sec-- tion, of-the water cooler shown in Fig-ure- 1.:

Figure aeectionabvievr taken on line's- 3 f of Figure 2.

wearer: 'is-a sectional viewtaken on'fline 4+4 of Figure 2: 7 v i Y said rcylifidrical n'leg -ito" theelower peritioni thereof, 1 which is substantially U-shaped aneliterminates ima bellihousmglzw The meat-(exchange unit 'ilB zrests P01151331) of-they; bell ihousingl 2 41 and comprises a KGYHIld-IififlrlrhOUSE-I ing 26 havingrtubeiSheetsaiCh-and 2 8 31t1'th8110WBE 3 and upper ends thereof, thereby defining a closed chamber 29, through which water being cooled is circulated.

Each of the tube sheets 27 and 28 is formed with a plurality of apertures such as 30, through which tubes 3| are extended, thereby creating a plurality of communicating conduits between the bell housing 24 and the upper'end of the heatexchange unit l6 for the passage of refrigerant.

The heat-exchange unit |6 also has an upper housing 33, the interior of which is in communication with the interior of the header 3 by means of a nipple 34, communicating with the interior of the header I3 at a point above the normal level of the liquid refrigerant 22.

A plurality of baffles such as 40 and 4| are alternately disposed in the housing26 in spaced relation. Each of the baffles is formed with a plurality of apertures corresponding with the apertures 30, so that the tubes 3| can pass therethrough. H

Each of the baffles 46 and 4| conformssubstantially to the innersurface' of the cylindrical housing 26 except at one edge thereof, wherein it is spaced therefrom, thereby defining passages 42 and 43 alternately disposed on opposite sides of the cylindrical housing 26. It is obvious therefore, that a tortuous path is defined beween each successive bafile and through the alternately, oppositely spaced passages between the bafiies and the cylindrical housing'26.

The cylindrical housing 26 is formed with a boss 45 adapted to receive a discharge nipple 46 in communication with the interior of the heat-exchange unit.

A nipple 41 .is adapted to connect a supply pipe 46 into the lower region of the heat exchange unit l6 so that water introduced through the pipe 48 passes into the chamber 29 and moves upwardly through the above mentioned tortuous path. Such a construction results in a high degree of turbulence in the water and an intimate contact of all parts of the water with the walls of the tubes 3|, which carry liquid refrigerant, so that by the time the water has reached the discharge nipple 46 it is cooled to substantially the same temperature as the liquid refrigerant contained in the tubes.

The second depending column |1 extends inwardly into the header l3 and terminates at a point above the normal level of the liquid refrigerant 22. The upper end of the column I! is open and formed with a notch 50. The column terminates at the lower end in a U- shaped section having 'a bell housing 52 disposed. thereon and connecting said column H with the heat exchanger l8.

The heat exchanger 8 comprises a cylindrical housing 49 having tube sheets 53 and 54 at the upper and lower ends thereof, respectively, defining therebya chamber 55. A plurality of tubes 56 extends through the diaphragms 53 and 54 in a similar manner as the tubes 31 in the heat exchanger 6.

- The heat exchanger 8 is also provided with aplurality of bafiles 5'6 and 57 in spaced parallel relation having opposite ends cut oil to thereby define a tortuous path upwardly through said bafiles and around said tubes 56 in a manner similar to the heat exchanger 6 previously'described.

A water inlet conduit 65 is connected. to the interior chamber 55 of the heat-exchanger unit |8.- The water supply pipe 48 is connected into the chamber 55 by means of a nipple 59.

The heat exchanger I8 is capped by a bell housing '66 which is connected to a suction line 6| returning spent refrigerant gas to the compressor H] by means of nipples 62 and 63 and conduit 64. The conduit 64 runs through the header I3 and is surrounded by liquid refrigerant in the lower region thereof and by gaseous refrigerant in the upper region thereof.

A tube 16 having a closed bottom 1| is secured to the nipple 63 and depends into the liquid refrigerant 22 in spaced relation with respect to the conduit 64.

The conduit 64 is formed with an aperture 13 surrounded by a wall 14 so that gaseous refrigerant in the conduit 64 is communicated directly against the tube 10. A baffle 15 is disposed inside the conduit 64 to direct exhaust gases into the pocket defined by the aperture 13 and the walls 14.

A remote pressure bulb TI is disposed into the tube 10 so that a portion of the bulb is responsive to the temperature of the liquid refrigerant 22, and a portion thereof is responsive to super heated gases in the conduit64. For further details of the construction and operation of this liquid level control, reference is made to the copending application of Lee Roy Erwin and Joseph B. Grifiith, filed May 9, 1949, being Serial No. 92,102, for Control for Refrigeration System.

Liquid refrigerant is introduced into the header l3 and fills the cylindrical column l5 and the tubes 3|. In view of the fact that the tubes 3| absorb heat at a much higher ratio than the column |5, the refrigerant in the tubes will become g-asified and pass upwardly, thereby causing aflow 'of refrigerant downwardly through the column l5 and a continuous circulation. Gasified refrigerant is returned into the header l3, whence it passes into the vertical column downwardly and up through the heat exchange H3.

The gases passing through the tube i! into the-heat-exchange unit I 8 become superheated and are deflected in their upper travel by the baflie 15 against'the wall of the tube 10 so that in the event that-alarge load is placed on the heat-exchange unit the temperature of the temperature-responsive bulb T! will cause an opening of the expansion valve M to permit the introduction of more liquid refrigerant into the system.

v In the event that too much liquid refrigerant is introduced into the system, it will flow over through the notch 50, thereby tending to cool or lower the temperature of the superheated gases in the conduit 64 and hence the gases impinging against the wall of the tube 16. This willlower the temperature in the control bulb 17 and close the expansion valve.

Due to the relatively large surface area created by dividing the liquid refrigerant into a large number of small tubes such as 3|, large amounts of heat will be rapidly-absorbed, thereby causing rapid gasification of the liquid refrigerant and a high velocity flow through the tubes 3|. The high velocity flow tends to scour the walls thereof of any gas bubbles forming thereon, which increases the efficiency of the heat transfer. Movement of the refrigerant in the column I5 is both downwardly and slow so that gas bubbles may form on the inner wall thereof to act as an insulator and protect the column of liquid refrigerant contained therein, thereby further aiding in the circulation of refrigerant through the sysanswer tembecause bf the inereased atelati ve weight of the liquid refrigei ant in the" column: lover the weight of a the *refrigerant in the tubes 3 l lt will be understood 'that' the waterisupply pipe "48tanbe eoririe'et'edto the top oftthe'heat 6 41% exchange unit; as 'weii as the bottom; and thew. circulation of wate'r therein reversed;

In Figure 8 we il lttst rate a -medifie'atiom off our water*coo1er. In this modific'atiofman partsbearing-similar numerals are similar to these i partsiliiistrated-iri Fig ures'l toflfinclusiveyand l heretofore described-i The 'prineipaidifi'erenee lies in the construction of the-primaiyvheatexchange-units Iri this-modifieationwe have provideda header 13d, adapted to re'oei-ve liquid refrigerant 22".

The primary refrigerating system comprises i a depending cylinder 85 being open at" both ends} adapted to communicate the liquid refrigerant 2'2 tothe bottomthereof. A cyl'indr-icai' sheli 8=i is disposedin spaced concentric relation with re spect=to thecylinder 'tfi' and is formed'ivith" a reduced lower end 62 secured to the wall of the cylinder 8i? Many suitable means such as weld ing. Thel cyliiider flfi is formed With'a plurality of apertures 83 permitting communication of the liquid refrigerant from said cylinder into "the annular chamber defined" between the cylinder mfandthe shell EH; The annular chamber 83 is openatthe top'ahd iri-communicationw-ith the header -l3ot-so that liquid refrigerant passing downwardly through the cyliridei- 8E3 oan pass outwardly through theapert-ures 8301111110 the annular chamber 84 and hence upwardly into the header.

A third cylindrical member '35, defining a water jaektfis concentrically disposed about the shell 8i and spaced therefrom. Ari annular tub''sh'eet 851s secured between the water jacket' fifi and the cylinder 88 at botiitdpandbottom; and a piurality of tubes 81 extend "through said baifie:

Aeap BS-is disposedbver thelower end of-the water jackeflBB-f thereby defining a"manifd1'ci* chamber 83; Thetubes S7 forma plurality of" oommunieatirig paths forliquid iefrige1'a1'it" 'between the manifold chamber 89 andth interior 1 of the header i3-rt-a-nd terminate at a poi-ht at least above the normal level of the liduid'i'efrig erant Aplural-ity of haflies such as 8E) andfliaredis posed in spaced relation having alternate endsterminating in spacedrelation'from the interior" wall of the water jacket 85 to thereby define a* tortuous path between the lower end'of-the water compartmenhii and the upper end thereof. Water is introducedinto the water compartment 97 by means of an inlet pipe 92" and disei'ierged" therefrom by a discharge pipe 93''.

Liquid refrigerant is introduced into the header Mia and fills the interior-ofthe cylinder 50. some of "the refrigerant fills the'annula-r chamber 34" through the ap-ertures 83a which absorbsheat through the shell "8! from the water in'the Water ehamberfii. As heat is absorbed, the=refrigerantbecomes 'gasified and rises to the top," thereby carrying the heat==with it and efieetively ""1n'-s\.1-- lating the column-of refrigerantin' thecylinder?" til. Therefore, refrigerant will flow down through the -coi=umn 8t and upwardly into the "tubes 81? Eaeh of the tubes 31" is substantiaiiy smaller) in diameter than the diameter of the cylinder 8211-" thereby exposing substantiaily more "surface for heat absorption from the water in the" chamber 9T 5 to cause expansion and gasifieationof the liquid refrigerant: Thereis therefore acontinuousfl0w bottom-thereof, which said" aperture receives in cyl ir dei fl ian' Water being follows a memoirs paith 'upward-ly arotmd' a1t hate ends of the baffles which causes *2, hi h degree of tiii buienbe" timate ecot-rtadtwith the meiri geatiiig tubs 1 d that bythi t'im" ady 'td isciiarged thr'oueh th-e temperature thei eof" has-veeaehed' provided with tube sheets I04 and H15 at the" bott'ono?andtopfrespeotivekg A manifold Chamber I06 isdefiIIed at theflower end of thetahk and 'cap'assembly'byfthemap 10-3 and the dia phragm' 1M? I Each of thltu'be sheets 104' a d ifi 'is formed with a pi 'ii'ra'lityflofapertiir'es 1 01 in axial alig n merit witl'i'a corresponding aperture in the other diaphragm having "tubular *mem'bers *1 118 fitted" *therein in fluid-tight relation, thereby providing a oommunicationbe'tween the interiorof thetahk I 35 and the manifoid chamberint:

A "second tiibulejrmember I OS-is disposed comce'ntrically through each of'the tubes" H18 to -thr'ethe tubes ll i' 'wiii be so' supported in th ttubes Each of the bafiies H4 are formed i ri-plah to correspond with the-"-iriterioi'surfahe -"0f the cyiiiidef ifl"as-shown in Figiirell exoeptthat alternate "ends such" as H S and 4* upwardly throae 7:, be turbulent and inintimate contact with the exterior surface of the tubes I08. Therefore, heat exchange between the water contained inside the cylinder IIlI and the tubes I08 will be at a maximum.

Liquid refrigerant 22 contained in the tank I317 will pass downwardly through the tubes I 09 into the chamber I06, and because of the heat exchange between the tubes I08 and the water contained in the cylinder IOI, liquid refrigerant which also fills the annular chamber III), will absorb heat, vaporize and readily pass upwardly through the annular chamber I ID. The differential in hydrostatic pressure between the column of liquid refrigerant in the tubes I09 and the liquidrefrigerant in the annular passage II 0, will cause a continuous circulation of refrigerant downwardly through the tubes I09 and upwardly through the annular chamber I I0.

Whereas the other parts of the water cooling system are not illustrated in Figures 10 and 11, it will readily be understood that such will be employed, such as the overflow pipes I'l leading to the heat-exchange unit I8, the suction line 6| and back to the compressor and condenser circuit.

While we have herein shown and described our invention in what we have conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of our invention, which is not to be limited to the details disclosed herein, but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices.

Having described our invention, what we claim as new and desire tosecure by Letters Patent is:

1. A water cooler comprising a flooded coil refrigerating system, and a heat exchange unit, said flooded coil system having a header tank for the reception of liquid refrigerant, an expansion loop depending from said header tank and in communication with the interior thereof and having a cylindrical depending leg and a coaxial return leg defining an annular passage for the return of refrigerant into said header tank, said heat exchange unit having a cylindrical shell surrounding said expansion loop and a plurality of bafiles disposed in spaced horizontal relation therein through which said expansion loop passes, each of said baflies being in substantially complete'circumferential abutment against the inner surface of said'shell and having one edge thereof in spaced relation from said shell defining a passage, the passage of each contiguousbaflle being on diametrically opposed sides, and inlet and discharge passages communicating with the interior of said shell, whereby water entering said inlet follows a tortuous, turbulent path in intimate contact with said refrigerant loop to be cooled thereby.

2. A water cooler comprising a flooded coil refrigerating system, and a heat exchange unit, said flooded coil system having a header tank for the reception of liquid refrigerant, a plurality of expansion loops depending from said header tank and in communication with the interior thereof, each said loop comprising a vertically disposed inner tube in communication with the interior of said header tank and a-coaxial outer tube disposed around said inner tube defining an annular passage for the return of refrigerant to said header tank, said heat exchange unit having a-cylindrical shell surrounding said expansion loops and a plurality of baflles disposed in spaced horizontal relation therein through which each of said loops passes, each of said baflies being in substantially complete circumferential abutment against the inner surface of said shell and having one edge thereof in spaced relation from said shell defining a passage therebetween, the passage of each contiguous baffle being on diametrically opposed sides, and inlet and dis charge passages communicating with the interior of said shell, whereby water entering said inlet follows a tortuous, turbulent path in intimate contact with said refrigerant loop return tube to be cooled thereby.

3. A water cooler comprising a refrigerating system having a compressor, a condenser, a receiver, an expansion valve adapted to control the flow of liquid refrigerant from said receiver, a header tank to receive liquid refrigerant from said expansion valve, and a refrigerating loop in communication with the interior of said header having a. depending leg of relatively large diameter and a return leg of relatively small diameter, whereby a circulation of refrigerant is caused to flow through said loop, a first heat exchange unit comprising a cylindrical housing having a plurality of horizontally spaced baffles, alternate bafiies of which have opposite edges spaced from the inner surface of said shell to thereby define a tortuous passage through said shell, said return leg being positioned to pass through each of said bafiies and being continuously in said tortuous'passage, control means for regulating the level of refrigerant in said tank comprising a conduit loop having one end in communication with the interior of said tank and the other end passing therethrough and in communication with said compressor and temperature responsive pressure bulb in heat-exchanging relation with gases in said other end and liquid refrigerant in said header tank and means for communicating the pressure in said bulb to said expansion valve, a second heat exchange unit to precool water before entering said first heat exchange unit and comprising a shell disposed surrounding said leg in communication with said compressor and having a tortuous path therein, and means connecting said precool heat exchange unit with said first mentioned heat exchange unit.

4. A water cooler comprising a refrigerating system having a compressor, a condenser, a receiver, an expansion valve adapted to control the flow of liquid refrigerated from said receiver, a header tank to receive liquid refrigerant from said expansion valve, a refrigerating loop having two ends in open communication with the interior of said header and having a depending leg of relatively small surface area compared to 'its volume and a plurality of return legs having relatively large surface compared to their total volume, whereby a circulation of refrigerant is caused to fiow through said loop, a, first heat exchange unit comprising a, cylindrical housing having a plurality of horizontally spaced baffles, alternate bafiles of which have opposite edges spaced from the inner surface of said shell to thereby define a, tortuous passage through said shell, said return leg being positioned to pass through each of said bafiles and being continuously in said tortuous passage, control means for regulating the level of refrigerant in said tank comprising a conduit loop having one end in communication with the interior of said tank and the other end passing therethrough and in communication with said compressor and temperature responsive pressure bulb in heat-exchanging unit with said first mentioned heat exchange unit.

5. A water cooler comprising a refrigerating system having a compressor, a condenser, a re ceiver, and an expansion valve adapted to control the flow of liquid refrigerant from said receiver,

a header tank to receive liquid refrigerant from 7 said expansion valve, a refrigerating loop having its ends in open communication with the interior of said header and comprising a depending leg of relatively large diameter and a plurality of return legs each of relatively small diameter, whereby a circulation of refrigerant is caused to flow through said loop, a heat exchange unit com prising a cylindrical housing having a plurality of horizontally spaced baflies, alternate baffles of which have opposite edges spaced from the inner surface of said shell to thereby define a tortuous passage through said shell, said return leg being positioned to pass through each of said baffies and being continuously in said tortuous passage, control means for regulating the level of refrigerant in said tank comprising a conduit loop having one end in communication with the interior of said tank and the other end passing therethrough and in communication with said compressor and temperature responsive pressure second heat exchange unit to precool water before entering said first heat exchange unit and comprising a shell disposed surrounding said leg in communication with said compressor and having a tortuous path therein, and means connecting said precool heat exchange unit with said first mentioned precool unit.

6. Refrigerating apparatus comprising in combination a header tank, means to admit liquid refrigerant to said tank, a first expansion loop depending from said header tank, both ends of said first loop communicating with the interior of said tank whereby refrigerant flows down one leg of said first loop and up the other leg, the upflow leg of said first loop including a heat exchanger effective to transfer heat from material to be cooled to refrigerant in said first loop, whereby liquid refrigerant is vaporized in said upflow leg and returns to said tank in vapor form, an outlet expansion loop depending from said tank having a downflow leg communicating with the interior of said tank substantially above the bottom there of, and having an upflow leg adapted to be connected to a refrigerant compressor, whereby said outlet loop normally receives only vaporized refrigerant from said tank, and receives liquid refrigerant only when the liquid level in the tank rises above the inlet of said outlet loop, the upflow leg of said outlet loop including a heat exchanger adapted to extract heat from material to be cooled, a temperature sensitive element in thermal association with the upflow leg of said outlet loop, and means responsive to said temperature sensitive element to control admission of liquid refrigerant to said header tank in accordance with the temperature of said element.

7. In refrigerating apparatus, the combination of a header tank, means for admitting liquid refrigerant into said tank, a first expansion loop depending from said tank, each end of said loop communicating with the interior of said tank, said first loop having a downflow leg and an upflow leg including a heat exchanger adapted to transmit heat from material to be cooled to refrigerant in said first loop, whereby liquid refrigerant flows from said tank into said first loop, is vaporized in the upflow leg thereof, and. returns in vapor form to said tank, and an outlet expansion loop depending from said header tank and having a downfiow leg communicating with the interior of said tank above the bottom thereof, and an upfiow leg adapted to be connected to a refrigerant compressor, whereby said outlet loop normally receives only vaporized refrigerant, and liquid refrigerant flows thereinto only when the liquid level in said tank rises above the inlet to said outlet loop, the upflow leg of said outlet loop including a heat exchanger adapted to convey heat to refrigerant in said outlet loop from material to be cooled.

8. In combination in refrigerating apparatus, a header tank adapted to receive liquid refrigerant, an inlet for admitting liquid refrigerant to said tank, an outlet expansion loop depending from said header tank and having a downflow leg in communication with the interior of said tank above the bottom thereof, and an upfiow leg adapted to communicate with a vapor compressor, said upflow leg including a heat exchanger adapted to transfer heat from material to be cooled to refrigerant in said upflow leg, said outlet loop normally evacuating vaporized refrigerant from said tank but receiving liquid refrigerant when the liquid level in said tank rises above the inlet of said outlet loop, a temperature sensitive element in thermal association with the upflow leg of said outlet loop, and means responsive to said temperature sensitive element to control admission of liquid refrigerant into said header tank in accordance with the temperature in said loop.

LEE ROY ERWIN.

JOSEPH B. GRIFFITH.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,694,369 Burdick Dec. 11, 1928 1,829,865 Kleucker Nov. 3, 1931 1,923,170 Slagel Aug. 22, 1933 1,974,736 Candor Sept. 25, 1934 2,434,374 Tull Jan. 13, 1948 2,478,863 Davis Aug. 9, 1949 2,572,501 Matteson Oct. 23, 1951 

